In many industries, and for many reasons, it may be desirable to noninvasively determine, to some degree, the positioning of a component beneath a substrate, the substrate hiding the component from ordinary visual position inspections. For example, in the aircraft industry, component panels of the aircraft could be attached to a structural framework through the use of hidden fasteners. These hidden fasteners are generally concealed beneath an outer skin/surface of the aircraft panel to avoid creating unwanted irregularities in the surface of the panel which might adversely affect airflow over the surface.
One hidden fastener design is the advanced Rapid Access Panel system (“RAP”), disclosed in co-pending U.S. patent application Ser. No. 14/593,851, titled “Fluid-Actuated Fastening Device” and filed 9 Jan. 2015, which is hereby incorporated by reference in its entirety. RAP is a pneumatically actuated fastener, with the clamping assemblies linked internally so they simultaneously release or engage with application of air pressure. An RAP, or other, similar fastener, may be a relatively reliable high-strength fastener. However, the RAP fastener is generally not visible for inspections to assure that it is in the correct locking position, since it engages the panel from underneath, with no fastener indication or effect upon the top surface of the panel. It is important to be able to identify quickly and accurately that the panel has been sufficiently latched via the RAP system. Also, should a fastener fail, it is important to be able to quickly locate the damaged fastener for removal/replacement with minimal effect upon the panel system.